As is known, a bronchoaspiration apparatus, connectable to a ventilation circuit, comprises:                a vacuum generating and regulating device;        a catheter body comprising a transparent sleeve and a catheter; and        a bronchotracheal access valve connected mechanically to a connecting member for connection to a patient's body.        
A bronchoaspiration apparatus must ensure complete isolation of the suction catheter from the environment, to prevent contamination of the patient by the environment and vice versa, i.e. contamination of the environment by the patient.
In operation, after a first suction stage, the end portion of the catheter is normally flushed by injecting sterilized water or a saline solution through a passage provided for that purpose.
The flushing operation is potentially hazardous to the patient, particularly in the case of babies. That is, the operator may inadvertently inject the flush fluid without activating the flush fluid suction means; in which case, the flush fluid would flow directly into the patient's trachea, thus resulting in obvious damage, which is particularly serious in the treatment of babies.